Shimano FC-R7100 105 12 Speed Double ChainsetEngineered for the best combination of durability, rigidity and low weight performance, this 12 speed chainset is ideal for pairing up with the rest of the Shimano 105 Di2 groupset. Featuring a hollow aluminium crankarms with an anodised finish, it delivers extra protection against wear and corrosion as you conquer every mile on your road bike. Another benefit is the resin ribs on the back of this model's chainrings, which use Shimano 105's unique structural design to achieve further weight savings and crisp shifting performance.Hollowtech II TechnologyProviding the best balance of stiffness, strength, weight and rotating performance, the concept of Hollowtech II technology is focused on producing a superior crankset that will maximise your power transfer. The rigidity of the crankset ensures pedalling efficiency while its weight, a key element of the crankset, you want light, aids in cycling longer distances where you need to pedal more. Moreover, the Hollowtech II crankset has a high-precision sealing in the bearing area to increase durability maintaining the excellent rotating performance for long periods.Hollowglide TechnologyThis model features Hollowglide technology on its outer chainring. High rigidity hollow structure cuts down on weight yet maintains strength. Better power transfer and quicker and more precise front shifting.Shimano 105 Di2 brings electronic wireless shifting to a new set of riders. For those who have only experienced mechanical shifting and ergonomics, Shimano 105 Di2 represents a transformation of the road cycling experience.Features: Crankarm Material: Hollow Aluminium with an Anodised finish Use: Road Speed: 12 speed Spider/Gear Arms: 4 Q-Factor: 148mm Chainline: 44.5mm PCD: 110mm Compatible Chain: HG 12 speed Bottom Bracket Included: No, available separately Recommended Press Fit BB: SM-BB72-41B Recommended Threaded BB: SM-BBR60 Technology: Hollowtech II, HollowglideTechnologies: - Optimal balance of stiffness, strength, weight and rotational performance. - Hollowglide structure cuts weight yet maintains strength for better power transfer and quicker, more precise front shifting.Manufacturer's Part Numbers: FCR7100A04 Black 12 Speed 165mm FCR7100C04 Black 12 Speed 170mm FCR7100D04 Black 12 Speed 172.5mm FCR7100E04 Black 12 Speed 175mmA 2-year warranty is offered with all Shimano products from Chain Reaction Cycles (3 years on Dura-Ace and XTR products).Buy Shimano Components from Chain Reaction Cycles, the World's Largest Online Bike Store.